[R-390] re cost reduction ect ect

[bernie nicholson]

Thanks for the comments, Re the 390 series being AM receivers this is true but the only mods required are a product detector and a minor mod to the AGC attack and decay times to turn these radios into SSB radios PAR excellence , and the parameters of the mechanical filters in the 390A  especially the 2KHz filter as regards stop band attenuation and overall bandwidth characteristics make it pretty hard to beat even today especially for something in this price range, what I am trying to convey is the fantastic signal to noise ratio from this combination and lets face it signal to noise ratio is DIRECTLY related to BANDWIDTH and LC filters at this frequency cant compete with these parameters ,my radios all have product detectors fitted as per HAM Radio Mag 1975 , I have tried the 6BE6 circuit in the BFO socket and also the better arrangement is the 12AU7 circuit as per  THE FUNDAMENTALS OF SSB  in the ballast tube socket , one IF module has been also modified with asymmetrical upper and lower sideband filters in the 2Khz, and 4khz positions and 455.00KHz crystal BFO this also is a excellent ssb receiver, far superior to my 51S1 ect ect and far superior to my 390 rx ,Anyway guys that's MY Rave in the subject Hi